SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1fe8892f47d145c2fb7c4613fa32e3f1172b8ab304b1b7f910fd131c0bc9d56' 
  AND token = 'jWImlHBqruGos5z4L/+wWwqRjBqWodftKJXItbZSu/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}